Rate limiting code using Spray 1.0-M2, needs migration.

gistfile1.scala

  def rateLimit(action: String, subject: String, maxRequests: Int) = {
    val key = action + ":" + subject

    add(redis, key)
    val actionCount = count(redis, key, interval)

    transformRequestContext {
      ctx =>
        ctx.withResponseTransformed {
          response =>
            response.copy(headers =
              // Number of requests allowed for that IP address per interval
              CustomHeader("X-FeatureRateLimit-Limit", maxRequests.toString)
                // Number of seconds in the rate limit interval
                :: CustomHeader("X-FeatureRateLimit-IntervalSecs", interval.toString)
                // Number of requests remaining.
                :: CustomHeader("X-FeatureRateLimit-Remaining", "" + (maxRequests - actionCount))
                // Time at which your quota is reset, in Unix epoch time
                :: CustomHeader("X-FeatureRateLimit-Reset", "" + (System.currentTimeMillis() + (redis.withClient(client => client.ttl(key).getOrElse(0l) * 1000))))
                :: response.headers)
        }
    } & filter {
      ctx =>
        if (actionCount >= maxRequests) {
          logger.warn("Rate limiting user '" + subject + "': exceeded max number of requests (" + maxRequests + ").")
          Reject(AuthorizationFailedRejection)
        }
        else Pass
    }
  }